35 millimeter slides are a major method of communication in our society at the present time. The current state of the art is to load the slides into a round "carousel" which fits onto a carousel slide projector. There are several million carousel projector systems currently in use. Literally every school, college, company and many individuals have these carousel projectors. One of the primary uses of a carousel projector system is for giving lectures. Typically, twenty to fifty slides are used per lecture. Rarely are fewer than ten slides used for a lecture nor are more than seventy commonly used for a lecture. There are two common carousel designs, one which holds eighty slides and one which holds one hundred and sixty slides.
The primary problem associated with the current carousel design is that its relatively large size prevents the lecturer from easily transporting the carousel. For example, the standard carousel is 2.38 inches tall and cannot fit into the average size briefcase. Nor can the standard carousel be efficiently stored on bookshelves. The result of the storage problem is that the slides are stored either in boxes where the slides are positioned adjacent one another, or in individual plastic sheets designed to hold twenty slides.
Accordingly, most lecturers transport the slides in the slide boxes or sheets. When a lecturer arrives at the site of the lecture, he or she must first find a functional carousel and then load each of the slides in the carousel. Each slide must be removed from the box or from the pockets in the plastic sheet and placed into the carousel. In doing so, it critical that the slides be placed in the carousel in the proper orientation and order. Therefore, the lecturer must spend the extra time necessary to insure that the orientation and the order of the slides are correct. Subsequent to the lecture, the lecturer must then remove the slides from the carousel and replace the slides in the storage boxes or the plastic sheets. Again, this provides another opportunity for the slides to be stored in the incorrect order. Furthermore, due to the handling of the slides, the slides often become damaged.
As can be seen from the foregoing, the present slide carousel system is not ideal. It is inefficient in terms of its relatively large size and its ability to be transported. The amount of time spent removing slides from the plastic sheets or from the storage boxes, loading the slides into a carousel, checking the orientation and reloading the slides subsequent to the lecture is in excess of ten minutes. This whole process makes inexperienced lecturers nervous and generates a large amount of unnecessary anxiety. In fact, it has been said that the major current limitation to the use of slides for communication is difficulty with storage of the slides and for transportation thereof.